1) Field of the Disclosure
The disclosure relates generally to threaded fasteners and fastener assemblies, and more particularly, to threaded fasteners and fastener assemblies with discontinuous threadforms.
2) Description of Related Art
Known threaded fastener assemblies comprising threaded fasteners in the form of bolts or screws, and corresponding threaded nuts, are used in numerous applications in the aerospace, military, automotive, construction, and other industries, to fasten component parts together and to fasten other components. Such known threaded fastener assemblies typically have threadforms with a helical, continuous, notch running the length of the threaded portion of either the male fastener or bolt portion or the female nut portion. Known threaded fastener assemblies depend upon a continuous raised threaded portion of the shaft of the male fastener to be in intimate contact with the leading surface and the trailing surface of the internal threads of the female nut. Notch sensitive materials may not be considered as candidate materials for forming known threaded fastener assemblies or fasteners, due to the design of the thread leading to sharp transitions in geometry (angles) and non-blended surfaces leading to sharp notches being formed (e.g., a 45 degree notch) at the base of the fastener thread. Notch sensitivity, understood by one skilled in the art, means a measure of the reduction in strength of a material caused by the presence of a notch or cut. Some materials are more notch sensitive than others. Low notch sensitivity is typically found with ductile materials and high notch sensitivity is typically found with brittle materials. Notch sensitivity of various plastics also differs, for example, nylon and unplasticized polyvinyl chloride (UPVC) are more notch sensitive than high impact polystyrene (HIPS).
Thus, known threaded fastener assemblies and fasteners can be limited in the materials that may be used to make them. Moreover, known threaded fastener assemblies and fasteners have continuous threads that require added material and thus can result in increased weight.
Accordingly, there is a need in the art for an improved threaded fastener and fastener assembly that provides advantages over known threaded fasteners and fastener assemblies.